Sometimes called the "eBay for drugs," it was the most popular of the world's online drug marketplaces, but since its shutdown similar websites peddling illicit products to order have sprung up in its place.

Customs investigations manager Maurice O'Brien said a "constant stream" of small consignments of drugs imported from websites were being intercepted at our border - with the the volume fluctuating from week to week.

The 2014 Global Drug Survey, conducted in partnership with global media partners including Fairfax Media, found of its respondents, which included 5731 in New Zealand, four per cent had bought drugs online.

Of those who reported buying drugs over the internet, about 45 per cent had done it for the first time in either 2012 or 2013.

While about a fifth of drug users said they had heard of sites such as Silk Road, only about 2 per cent had used drugs they had themselves ordered from it, and 4.8 per cent had used drugs bought from the site on their behalf.

Survey respondents using websites like Silk Road gave reasons such as lower prices, wider range, convenience and avoiding dealers for buying drugs online.

The prospect of a mail-order drug deal appeared to be tempting ordinary New Zealanders with previously unblemished records, Thomson said.

"It may look like easy cash, an easy way to get it if you don't know someone in the drug world . . . or have a fear of going into business with gangs."

People underestimated the risk of being caught importing illicit material, he said. "They think it's anonymous and of course it's not."

The damage to families when offending was discovered was financially and emotionally costly, he added.